For use as a mechanical support ring structure for a deployable space reflector antenna, it is known to provide ring-shaped support structures that can be converted, in space after being brought to space in a small-sized compact folded state, from the folded state into a deployed state for supporting a space reflector antenna, see e.g. U.S. Pat. No. 5,680,145. Such mechanical support ring structures can be used for space applications such as for supporting antenna reflectors for telecommunications, scientific experiments and Earth observations, as well as for supporting solar reflectors, solar sails and sun shields.
Also, it is known to provide such mechanical support ring structures on the basis of deployable pantograph mechanisms comprising a single ring-shaped pantograph (see e.g. RU 2 214 659 C2) or, as a double pantograph mechanism, two pantograph mechanisms which may be formed as a ring-shaped double pantograph having intercrossing pantograph lever pairs (see e.g. WO 03/003517 A1) or as upper and lower pantograph mechanisms which are connected by non-pantograph connecting sections (see e.g. GE P 2011 5298 B).
For use in space, e.g. for supporting deployable space reflector antennas, it is aimed at designing and constructing large deployable apertures (e.g. ranging from 4 to 50 m or more in diameter, when being deployed), which can at the same time provide the capabilities to be folded in a small-sized low-mass compact folded state (stowed state) to be efficiently stowed in a spacecraft during launch for the purpose of bringing the structure to space, and to be deployed in space into an expanded deployed state at a high deployment process reliability and deployment accuracy. At the same time, it is aimed at providing a high stiffness and stability of the deployed support structure. In order to provide more stability or for use in different applications, it may intended to provide not only a cylindrically shaped deployed support ring structure but also a conically shaped deployed support ring structure.
However, in the prior art, the known mechanical support ring structure which have a conical shape when being deployed have very complex structures and multi-component deployment mechanisms leading to complex and heavier structures which are larger-sized, when folded, and which need to be deployed in a very complex deployment process involving complicated mechanisms having less deployment reliability and less deployment accuracy. For example, GE P 2011 5298 B describes a conical mechanical support ring structure having a double-pantograph mechanism. However, the deployment process is complex and needs to occur at two stages involving plural components.
At the first stage, two separate double pantograph parts of the mechanical support ring structure are deployed independently (FIGS. 16 and 17 of GE P 2011 5298 B), the two separate double pantograph mechanisms being connected by additional connecting sections for closing to a ring-shaped support structure (the connecting sections are shown in FIGS. 31 to 35 of GE P 2011 5298 B). Then, in the second stage, after deployment of the pantograph sections, the complex multi-component connecting sections are converted for bringing the mechanical support ring structure into the conical deployed state.
As mentioned above, there is the problem that the deployment process of the support ring structure of GE P 2011 5298 B is complex and involves two stages which leads to lowered deployment accuracy and deployment reliability and, due to the additionally provided connecting section, which separate the double pantograph mechanisms, the folded state cannot be provided at small diameter having a compact size (see FIGS. 12 to 15 of GE P 2011 5298 B) and the stability of the deployed structure is lowered.
In view of the above-described problems of the prior art, it is an object of the present invention to provide a mechanical support ring structure which is multifunctional and allows to be deployed into a cylindrically-shaped deployed support ring structure and a conically-shaped deployed support ring structure by a simple, efficient, accurate and reliable deployment mechanism.
It is a further object of the present invention to provide a mechanical support ring structure that can be provided at low mass and with compact size in the folded state. It is a further object of the present invention to provide a mechanical support ring structure that provides high stability and stiffness after being converted into the deployed state.